Reaction product of high molecular
weight succinic acids and succinic
anhydrides with an ethylene poly-
amine



REACTION PRODUCT OF HIGH MOLECULAR WEIGHT SUCClNllC ACIDS AND SU'CCINICANHYDRIDES WITH AN ETHYLENE POLY- AMINE William M. 'Le Suer, Cleveland,and George R. Norman,

Lyndhurst, Ohio, assignors to The Luhrizol Corporation, Wickliife, Ohio,a corporation of Ohio No Drawing. Filed Mar. 30, 1959, Ser. No. 802,667

6 Claims. (Cl. 260-3265) This invention relates to a process for thepreparation of an oil-soluble product which is useful as a dispersingagent in lubricating compositions. The product is particularly useful inlubricating compositions intended for use in the crankcase of internalcombustion engines.

One of the principal problems associated with present day crankcaselubricants is that posed by the inevitable presence in the lubricant offoreign particles such as dirt, soot, water and decomposition productsresulting from breakdown of the oil. Even if there was none of thislatter contaminant present the very nature of the design of the moderninternal combustion engine is such that a significant amount of foreignmatter will accumulate in the crankcase. Perhaps the most important ofthese contaminants is water because it seems to be responsible for thedeposition of a mayonnaise-likesludge. It appears that if there were nowater present the solid components of the mayonnaise-like sludge wouldcirculate with the oil and be removed by the oil filter; It will bereadily appreciated that the deposition of the sludge presents a seriousproblem with respect to the efiicient operation of the engine and thatit is desirable to prevent such deposition of sludge-like material.

The presence of water and the precursors of sludge in a lubricating oilis dependent largely upon the operating temperature of the oil. If theoil is operated at a high temperature the water of course will beeliminated by evaporation about as fast as it accumulates. In theabsence of water, as stated above, the other foreign particles will beremoved by the filter. At low oil temperatures, on the other hand, waterwill accumulate and so consequently will sludge. It is apparent that theenvironment in which a crankcase lubricant is maintained will determineto a large extent the ultimate performance of that lubricant.

High operating temperatures are characteristic of a lubricant in anengine that is run at relative constant high speed. Thus in an enginethat is run at 60 mph. for a long period of time it is very unlikelythere would be any accumulation of water and it is similarly unlikelythat there will be any formation and deposition of sludge. But inordinary stop-and-go driving, as is the case with taxicabs, deliverytrucks, police cruisers, etc., the crankcase lubricant will bealternately hot and cold, an ideal environment for the accumulation ofwater. In such cases the formation of sludge is a serious problem. Thisproblem has been with the automotive industry for many years and itssolution has been approached by the use of known detergents such asalkaline earth metal phenates and sulfonates, but without notablesuccess. Although such known detergents are very effective in solvingthe detergency problems associated with motor oils at high temperatures,they have not been particularly effective in solving the problemsassociated with low temperature operation, or to put it better, thoseproblems which are associated with crankcase lubricants in engines whichare operated at alternating high and low temperatures.

It is accordingly a principal object of this invention to provide anovel process for the preparation of products which are effective asdispersants in lubricant compositions.

te States atent 3,172,392 Patented Mar. 9, i965 proved lubricantcompositions.

These and other objects of the invention are achieved.

by the process of preparing an oil-soluble acylated amine suitable foruse as a dispersant in lubricant compositions which comprises mixing asubstituted succinic compound selected from the class consisting ofsubstituted succinic acids having the structural formula and substitutedsuccinic anhydrides having the structural formula R-CHCO in whichstructural formulas R is a large, substantially aliphatic hydrocarbonradical having at least about 50 carbon atoms, with at least aboutone-half an equivalent amount of an ethylene amine, and heating theresulting mixture to effect acylati on and remove the water formedthereby.

It will be seen that the reaction of this process, involving anamidation of a dicarboxylic acid (or anhydride thereof) with apolyamine, can result in a simple acyclic diamide, a cyclic diamide, apolymeric amide or a combination of any of these types of products. Itwill be noted also that the amide groups may react further to form imidegroups and it is believed that a substantial amount of imide formationtakes .place in the process. Furthermore there is reason to believe thatin certain instances there is present in the product an appreciableproportion of amine carboxylate salt.

The size of the substituent of the succinic acid or anhydride is ofmajor importance in the process because it allows the preparation of aproduct which satisfies the objects of the invention, i.e., one which iseffective as a dispersant in low-temperature engine lubricants. It iscritically important that this substituent be large, that it have atleast about 50 carbon atoms in its structure. These substituent groupsare substantially aliphatic hydrocarbon radicals, including both alkyland alkenyl radicals. They are commonly derived from polyolefins such aspolyethylene, polypropylene, polybutylcne, etc., although they may bederived from any substantially aliphatic hydrocarbon.

The substituted succinic acids and anhydrides which are contemplated asa reactant in the process are readily available from the reaction ofmaleic anhydride with a. high molecular weight olefin or a chlorinatedhigh molecular weight olefin. The product from such a reaction is thecorresponding alkenyl succinic anhydride The reaction involves merelyheating the two reactants at a temperature of about ISO-200 C. Thereactions in each case are illustrated by the following equations.

It will be appreciated that the reactions may not go precisely asindicated in the above equations, especially with respect to theparticular carbon'atom of the olefin or chloride reactant whichultimately becomes attached to the maleic acid or anhydride reactant,but other than this the equations are believed to be illustrative.Furthermore although the product of this reaction has been indicated asbeing an alkenyl succinic anhydride it is apparent that similar productscan be prepared by this process in which the substituent is somethingother than an alkenyl group. For the purposes of this invention thissubstituent should, however, be a substantially aliphatic group and inmost cases of course it will be an alkyl or alkenyl group. In somecases, however, it may well be desirable to employ a substitutedsuccinic anhydride in which the substituent is derivedfrom a copolymerof styrene and isobutylene, or of a substituted styrene and some otheraliphatic olefin. In these latter cases the copolymer will besubstantially aliphatic, that is, the composition of the copolymer willbe predominantly aliphatic, i.e., more than about 90% of the monomericunits will be those of the aliphatic monomer. I

As mentioned earlier the size of this substituent group appears todetermine the effectiveness of the product of the process of theinvention as a dispersant in motor oils. Substituted succinic anhydridesand their derivatives have been known for some time and it has likewisebeen known that these compounds are useful in lubricants, but theirutility heretofore has been predicated upon their rustpreventingproperties, corrosion-inhibiting properties, viscosity-temperaturecharacteristics, etc. The usefulness of compositions of this type asdispersants has never been realized and an important aspect of thisinvention resides in the discovery that by increasing the size of thisparticular substituent an entirely new property, i.e., dispersancy, canbe incorporated into the composition.

The most commonly used sources of these substantially aliphatichydrocarbon substituents are the polyolefins. These are illustrated bypolyethylene, polypropylene, polyisobutylene, etc. A particularlypreferred polyolefin for this use is polyisobutylene. Thus thecondensation of a polyisobutylene having a molecular weight of 750 withmaleic anhydride yields an alkenyl succinic anhydride which upon furtherreaction with an ethylene amine produces an especially effectivelubricating oil dispersant. Polyisobutylenes of this particularmolecular weight are quite economically available and the effectivenessof products prepared from this material makes this starting materialparticularly desirable for use in a process of this invention.

The substituted succinic anhydride ordinarily is reacted directly withthe ethylene amine although in some circumstances it may be desirablefirst to convert the anhydride to the acid before reaction with diamine.In other circumstances it may be desirable to prepare the substitutedsuccinic acid by some other means and to use an acid prepared by suchother means in the process. In any event either the acid or theanhydride may be used in the process of this invention.

The term ethylene amine is used in a generic sense to denote a class ofpolyamines conforming for the most part of the structure It in which 2:is an integer and -R is a low molecular weight alkyl radical orhydrogen. Thus it includes for example ethylene diamine, diethylenetriamine, triethylene tetramine, tretaethylene pentamine, pentaethylenehexamine, etc. These compounds are discussed in some detail under theheading Ethylene Amines in Encyclopedia of Chemical Technology, Kirk andOthmer, vol. 5, pages 898-905, Interscience Publishers, New York (1950).Such compounds are prepared most conveniently by the reaction ofethylene dichloride with ammonia. This process results in the productionof' somewhat complex mixtures of ethylene amines. including cycliccondensation products such as piperazines and these mixtures find use inthe process of this invention. On the other hand quite satisfactoryproducts may be obtained also by the use of pure ethylene amines. Anespecially useful ethylene amine, for reasons of economy as well asellectivcness as a dispersant, is a mixture of ethylene amines preparedby the reaction ethylene chloride and ammonia, having a compositionwhich corresponds to that of tetracthylcne pentamine. This is availablein the trade under the trade name Polyamine H.

It has been noted that at least one half of a chemical equivalent amountof the ethylene amine per equivalent of substituted succinic anhydridemust be used in the process to produce a satisfactory product withrespect to dispersant properties and generally it is preferred to usethese reactants in equivalent amounts. Amounts up to 2.0 chemicalequivalents (per equivalent of substituted succinic anhydride) have beenused with success, although there appears to be no advantage attendantupon the use of more than this amount. The chemical equivalency of theethylene amine reactant is upon the nitrogen content, i.e., one havingfour nitrogens per molecule has four equivalents per mole.

The reaction of the process involves a splitting out of water and thereaction conditions are such that this water is removed as it is formed.Presumably the first principal reaction that occurs, following saltformation, is the formation of a half amide R-CHCO R--(.IICOOII 0 InNRcrncoNiIR CIl CO followed then by salt formation R-CHCOOH n-orrcoorntirn+1-nNR HgCONHR Il CONHR and involving finally dehydration of this saltto form the product fore there is also some imide-formation.

Specific examples of the process by which the products of this inventionmay be prepared are as follows.

EXAMPLE 1 A polyisobutenyl succinic anhydride was prepared by thereaction of a chlorinated polyisobutylene with maleic anhydride at 200C. The polyisobutenyl radical had an average molecular weight of 850 andthe resulting alkenyl succinic anhydride was found to have an acidnumber of 113 (corresponding to an equivalent weight of 500). To amixture of 500 grams (1 equivalent) of this polyisobutenyl succinicanhydride and 160 grams of toluene there was added at room temperature35 grams (1 equivalent) of diethylene triamine. The addition was madeportionwise throughout a period of 15 minues, and an initial exothermicreaction caused the temperature to rise to 50 C. The mixture then washeated and a water-toluene a'zeotrope distilled from the mixture. Whenno more water would distill the mixture was heated to C. at reducedpressure to remove the toluene. The residue was diluted with 350 gramsof mineral oil and this solution was found to have a nitrogen content of1.6%.

EXAMPLE 2 The procedures of Example I was repeated using 3| grams (1equivalent) of ethylene diamine as the amine 5 reactant. The nitrogencontent of the resulting product was 1.4%.

EXAMPLE 3 The procedure of Example 1 was repeated using 55.5 grams (1.5equivalents) of an ethylene amine mixture having a compositioncorresponding to that of triethylene tetramine. The resulting producthad a nitrogen content of 1.9%.

EXAMPLE 4 The procedure of Example 1 was repeated using 55.0 grams (1.5equivalents) of triethylene tetramine as the amine reactant. Theresulting product had a nitrogen content of 2.2%

EXAM PLE 5 ture was heated to distill the watentoluene azeotrope andthen to 15 C. at reduced pressure to remove the remaining toluene. Theresidual polyamide had a nitrogen content of 4.7%.

EXAMPLE 6 The procedure of Example 1 was repeated using 46 grams (1.5equivalents) of ethylene diamine as the amine reactant. The productwhich resulted had a nitrogen content of 1.5%.

EXAMPLE 7 A polyisobutenyl succinic anhydride having an acid number of105 and an equivalent weight of 540 was prepared by the reaction of achlorinated polyisobutylene (having an average molecular weight of 1,050and a chlorine content of 4.3%) and maleic anhydride. To a mixture of300 parts by weight of the polyisobutenyl succinic anhydride and 160parts of weight of mineral oil there was added at 65-95 C. an equivalentamount (25 parts of weight) of Polyamine H (identified in Example Thismixture then was heated to 150 C. to distill all of the water formed inthe reaction. Nitrogen was bubbled through the mixture at thistemperature to insure removal of the last traces of water. The residuewas diluted by 79 parts by weight of mineral oil and this oil solutionfound to have a nitrogen content of 1.6%.

EXAMPLE 8 A mixture of 2,112 grams (3.9 equivalent) of thepolyisobutenyl succinic anhydride of Example 7, 136 grams (3.9equivalents) of diethylene triamine, and 1,060 grams of mineral oil washeated at 140450 C. for one hour. Nitrogen was bubbled through themixture at this temperature for four more hours to aid in the removal ofwater. The residue was diluted with 420 grams of mineral oil and thisoil solution was found to have a nitrogen content of 1.3%.

EXAMPLE 9 To a solution of 1,000 grams (1.87 equivalents) of thepolyisobutenyl succinic anhydride of Example 7, in 500 grams of mineraloil there was added at 8595 C. 70 grams (1.87 equivalents) oftetracthylene pentamine. The mixture then was heated at 150-165 C. forfour hours, blowing with nitrogen to aid in the removal of water. Theresidue was diluted with 200 grams of mineral oil and the oil solutionfound to have a nitrogen content of 1.4%.

, EXAMPLE 10 A polypropyenyl succinic anhydride was prepared by thereaction of a chlorinated polypropylene (having a molecular weight ofabout 900 and a chlorine content of 4%) and maleic anhydride at 200 C.The product had an acid number of 75. To a mixture of 390 grams (0.52equivalent) of this polypropenyl succinic anhydride, 500 grams oftoluene, and 170 grams of mineral oil there was added portionwise 22grams (0.52 equivalent) of Polyamine H. The reaction mixture was heatedat reflux temperature for three hours and water removed from anazeotrope with toluene. The toluene then was removed by heating to 150C./20 millimeters. The residue was found to contain 1.3 of nitrogen.

EXAMPLE 11 A substituted succinic anhydride was prepared by reactingmaleic anhydride with a chlorinated copolymer of isobutylene andstyrene. The copolymer consisted of 94 parts by weight of isobutyleneunits and 6 parts by weight of styrene units, had an average molecularweight of 1,200, and was chlorinated to a chlorine content of 2.8% byweight. The resulting substituted succinic an- I hydride had an acidnumber of 40. To 710 grams (0.51

equivalent) of this substituted succinic anhydride and 500 grams oftoluene there was added portionwise 22 grams (0.51 equivalent) ofPolyamine H. The mixture was heated at reflux temperature for threehours to remove by azeotropic distillation all of the water formed inthe reaction, and then at 150 C./20 millimeters to remove the toluene.The residue contained 1.1% by weight of nitrogen.

. EXAMPLE 12 A substituted succinic anhydride was prepared by reactingmaleic anhydride with a chlorinated copolymer of isobutylene-andisoprene. The copolyrner consisted of 99 parts by weight of isobutyleneunits and 1% by weight of isoprene units. The molecular weight of thecopolymer was 28,000 and the chlorine content of the chlorinatedcopolymer was 1.95%. The resulting a1- kenyl succinic anhydride had anacid number of 54. To a mixture of 228 grams (0.22 equivalent) of an oilsolution of this alkenyl succinic anhydride, 58 grams of additionalmineral oil, 500 grams of toluene and 9.3 grams (0.22 equivalent) ofPolyamine H was heated at C. for three hours, water being removed froman azeotrope with toluene. When all of the water had thus been removedthe toluene was distilled by heating to C./ 20 millimeters. The residuewas found to have a nitrogen content of 1.1%.

EXAMPLE 13 A polyisobutenyl succinic anhydride was prepared by thereaction of a chlorinated polysiobutylene with maleic anhydride. Thechlorinated polyisobutylene had a chlorine content of 2% and an averagemolecular weight of 11,000. The polyisobutenyl succinic anhydride had anacid number of 48. A mixture of 410 grams (0.35 equivalent) of thisanhydride, 15 grams (0.35 equivalent) of Polyamine H and 500 grams oftoluene was heated at reflux temperature for four hours to remove waterfrom an azeotrope with toluene. The toluene then was removed by heatingto 150 C./20 millimeters. The nitrogen content of the residue was 1.3%.

EXAMPLE 14 The procedure of Example 5 was repeated except that 0.94equivalent of Polyamine H was used instead of 1.55 equivalents. Thenitrogen content of the product was 3%.

EXAMPLE 15 A polyisobutenyl-substituted succinic acid was prepared byhydrolysis of the corresponding anhydride (prepared in turn by thecondensation of a chlorinated poly- 7 isobutylene and maleic anhydride).To 1,152 grams (1.5 equivalents) of a 70% mineral oil solution of thispolyisobutenyl succinic acid having an acid number of 62 there was addedat room temperature 59.5 grams (1.5 equivalents) of Polyamine H. Thismixture was heated at ISO-167 C. for 7 hours during which time a totalof 19.5 grams of water was distilled from the mixture. The residue wasdiluted with 174 grams of mineral oil and then filtered at 150 C. Thefiltrate had a nitrogen content of 1.6%.

EXAMPLE 16 A mixture of 1,056 grams (2.0 equivalents) of thepolyisobutenyl succinic anhydride of the preceding example (in which thepolyisobutenyl group has a molecular weight of 850), 89 grams (2.0equivalents) of di- (-1,2-propylene) triamine (having a nitrogen contentof 31.3%), 370 grams of mineral oil and 100 grams of toluene was heatedat reflux temperature (ISO-190 C.) for hours. A total of 18 grams ofwater was collected from the water-toluene azeotrope. The residue washeated to 150 C./20 mm. to remove any last traces of water which mighthave remained. The nitrogen analysis of this residue was 1.9%.

EXAMPLE 17 A polyisobutylene having an average molecular weight of50,000 was chlorinated to a chlorine content of by weight. Thischlorinated polyisobutylene was reacted with maleic anhydride to producethe corresponding polyisobutenyl succinic anhydride having an acidnumber of 24. To 6,000 grams (2.55 equivalents) of this anhydride therewas added portionwise at 70-105" C. 108 grams (2.55 equivalents) ofPolyamine H over a preiod of 45 minutes. The resulting mixture washeated for four hours at l60-l80 C. while nitrogen was bubbledthroughout to remove water. When all of the water had been removed theproduct was filtered and the filtrate found to have a nitrogen contentof 0.6%.

EXAMPLE 18 An alkenyl succinic anhydride in which the alkenyl group hasless than 50 carbon atoms was prepared from a polyisobutylcne having anaverage molecular weight This polymer was chlorinated to a chlorinecontent of 9.7% and then reacted with maleic anhydride. The resultingpolyisobutenyl succinic anhydride had an acid number of 190 and anequivalent weight of 300. The procedure of Example 1 was followed using1.0 equivalent of this polyisobutenyl succinic anhydride and 1.0equivalentof Polyamine H. The resulting product then was diluted withmineral oil to a 58% solution therein; the nitrogen content was 3.2%.

EXAMPLE 19 Another alkeny] succinic anhydride in which the alkenyl grouphas less than 50 carbons was prepared by alkylation of maleic anhydridewith tetrapropylene. Equivalent amounts of this tetrapropenyl succinicanhydride and triethylene tetramine in toluene were heated at refluxtemperature until substantially all of the water was removed. Thetoluene then was removed by heating at 155% C. under reduced pressureand the residue was dissolved in chlorine oil to a 60% solution. Thisoil solution was found to have a nitrogen content of 4.8%.

The dispersant qualities of the products prepared by the process of thisinvention are most striking when used in mineral oil lubricants. Theseproducts are miscible in such lubricants in all proportions, andnormally they are employed in concentrations ranging from about 0.1% toabout 5% by weight of the total lubricant composition. The optimumconcentration ordinarily depends upon the nature of the particular basemineral oil stock and the type of service to which the lubricant is tobe subjected. The optimum amount will lie within the narrower range offrom about 0.5% to about 3%.

As noted before, the addiiton to a lubricating composition of theproducts of this invention results in a marked improvement in thedispersant qualities of the lubricant, and a mineral oil solutioncontaining only a small percentage of a product of this invention is asatisfactory lubricant in many commercial applications. Most commerciallubricants, however, are subjected to a wide variety of difficultenvironments and it is necessary for the satisfactory performance ofthese lubricants to employ more than one type of additive. Thus althoughthe products of this invention are notably effective in the improvementof dispersant properties, particularly for low temperature operations,it frequently is necessary to use this dispersant product in combinationwith other types of additives such as metallic dispersants, corrosionand oxidation inhibitors, extreme pressure agents, viscosity improvers,pour point depressants, foam inhibitors, etc.

An especially useful combination of additives for use in crankcaselubricants is the combination of the type of additive prepared by theprocess of this invention and a metallic dispersant. Such metallicdispersants include for example the alkaline earth metal sulfonates,carboxylates and phenates. The alkaline earth metal sulfonates areespecially useful in this combination and they include specifically theneutral and basic barium alkylaromatic sulfonates, calcium mahoganysulfonates and calcium alkyl-aromatic sulfonates. The term basicsulfonates is used to denote those compositions which contain astoichiometrically excessive amount of metal, usually as the metalcarbonate, with respect to the sulfonate anion of the composition.

Another very useful combination of additives comprises the type ofadditive prepared by the process of this invention and a corrosioninhibitor. Such corrosion inhibitors include the metalphosphorodithioates, the various olefin-phosphorus sulfide reactionproducts and phenolic compounds. A particularly satisfactory metalphosphorodithioate is the zinc dialkyl phosphorodithioate in which thealkyl groups are C -C and a similarly very useful olefin-phosphorussulfide reaction product is a turpentine-phosphorus pentasulfidecondensation product.

The utility of the dispersant additives of this invention is shown bythe results of an evaluation of the crankcase lubricants used intaxicabs which had been operated for over 50,000 miles each. In thistest ten 6-cylinder 1958 Chevrolet cars (with no oil filters) wereoperated as a fleet of taxicabs. In each case the crankcase lubricantwas a sulfur-refined Mid-Continent petroleum oil having a viscosity of185 SUS/ F. and a viscosity index of 112, and containing 5.9% by volumeof a polyalkylmethacrylate viscosity index improver and 0.59% by volumeof a zinc dialkyl phosphorodithioate (the alkyl groups being isobutyland a mixture of primary amyl). Crankcase oil drains were taken fromeach car at oilchange intervals of about 3,000 miles of service andthese drains combined. A 30-cc. sample of each of the combined drainswas mixed with 1% by weight of the dispersant additive to be tested and2% by weight of water. This mixture then was homogenized, placed in a100-cc. graduated cone-shaped centrifuge tube and centrifuged for twohours at 1500 r.p.m. The various dispersants were evaluated by notingthe volume of deposited sediment in terms of cubic centimeters and alsothe turbidity of the supernatant oil layer. It is apparent that the moreeffective dispersants will give test results which show a minimum ofdeposited sediment and a relatively hazy supernatant oil layer.

The clarity of the supernatant oil layer was determined by the amount oflight transmitted through it from a 3-volt, 0.75 watt incandescent bulb.

The results of these tests are shown in Table I.

The dispersant properties of the compositions of this invention may beillustrated also by the results of an oxidation-dispersancy test whichis useful as a screening test for determining the effectiveness of thedispersant additive under light-duty service conditions. In this test a350-cc. sample of a lubricating oil containing the dispersant additiveis placed in a 2" x 15" borosilicate tube. A 1%" x 5 /8 SAE 1020 steelpanel is immersed in the oil. The sample then is heated at 300 F. for 48hours while air is bubbled through the oil at the rate of 10 liters perhour. The oxidized sample is cooled to 120 F., homogenized. allowed tostand at room temperature for 24 hours and then filtered through twolayers of No. 1 Whatman filter paper at mm. Hg pressure. The weight ofthe precipitate, washed with naphtha and dried, is taken as a measure ofthe effectiveness of the dispersant additive, i.e., the greater thisweight of precipitate the less effective the dispersant.

Two modifications of the above procedure may be employed; both make thetest more severe; one consists of extending the test from 48 hours to 96hours, and the other involves adding 0.5% of water, based on the weightof the test sample, to the oxidized oil before homogenization.

The lubricating oil employed in this test (Table II) was a Mid-Continentconventionally refined petroleum oil having a viscosity of about 200SUS/100 F., and containing 0.001% by weight of iron naphthenate (topromote oxidation).

Table II Additive Tested (1.5% by weight of diiiieiita ie tig fifiggg giree chemical) deposit,

[100 ml. of oil tested None. 144 None. 275 (1)) None. 1, 000 (a,b) Priorart product of Example 18. 738 Prior art product of Example 19. 1,060(b) Product of Example 1 0.7 (b) Product of Example 2 0.7 (b) Product ofExample 3. 1.0 (1)) Product of Example 4. 1.2 (b) Product 01 Example5. 1. 5 (b) Product of Example 6. 0. 7 (1)) Product of Example 9... 0. 5(b) Product of Example 10.. 3. 2 (1)) Product of Example 11.. 10.2 (1))Product of Example 1 19. 5 (b) Product of Example 13.. 2. 7 (1)) Productof Example 14.. 0.3 Product of Example 14.. 1. 2 (h) Product of Example14.. 1.7 (n,b) Product of Example 15.. 1. 3 (b) Product 01 Example 160.9 (b) Modification "3": 96 hours testing.

Modification b: 0.5% of water used in the test.

Further illustration of the usefulness of the products of this inventionas dispersants in motor oils was gained from a modified version 1 of theCRC-EX-3 Engine Test. This test is recognized in the field as animportant test bywhich lubricants can be evaluated for use underlightduty service conditions. In this particular test the lubricant isused in the crankcase of a 1954 o-cylinder Chevro- 1 Ordinarily thistest lusts for 96 hours.

let Powerglide engine for 144 hours under recurring cycling conditions,each cycle consisting of:

2 hours at an engine speed of 500:25 r.p.m. under zero load at an oilsump temperature of 100-125 F.; air-fuel ratio of 10:1;

2 hours at an engine speed of 2500:25 r.p.m-. under a load of 40brake-horsepower at an oil sump temperaiture of 160170 F.; air-fuelratio of 16:1;

2 hours at an engine speed of 2500125 r.p.m. under a load of 40broke-horsepower at an oil sump temperature of 240-250 F.; air-fuelratio of 16:1.

After completion of the test, the engine is dismantled and various pantsof the engine are examined for engine deposits. The lubricant dispersantaddition agent is then rated according to (1) the extent of pistonring-filling,

(2) the amount of sludge formed in the engine (on a scale of -0, 80being indicative of no sludge and 0 being indicative of extremely heavysludge), and (3) the total amount of engine deposits, i.e., sludge andvarnish, formed in the engine (on a scale of -0, 100 being indicative ofno deposits and 0 being indicative of extremely heavy deposits). Theresults are summarized in Table III.

Other modes of applying the principle of the invention may be employed,change being made as regards the details described, provided. thefeatures stated in any of the following claims, or the equivalent ofsuch, be employed.

We therefore particularly point out and distinctly claim as ourinvention:

1. The product prepared by the process which cornprises mixing asubstituted succinic compound selected from the class consisting ofsubstiuted succinic acids having the structural formula noncoo1r HnCOOHand substituted succinic anhydrides having the structural formulaR-CHC9\ O CHQCO in which structural formulas R is a large substantiallyaliphatic hydrocarbon radical having at least about 50 carbon atoms,with at least about one-half an equivalent amount of an ethylenepolyamine per equivalent of substituted succinic compound, and heatingthe resulting mixture to eifect acylaition and remove the water formedtheireby.

2. The product prepared by the process which comprises mixing asubstituted succinic anhydride having the structural formula R-(lII-OgHQCO/ wherein R is a large, substantially aliphatic hydrocarbon radicalhaving at least about 50 carbon atoms, said suibstituted suocinicanhydride having been prepared by the reaction of maleic anhydride witha high molecular weight olefin; with at least about one-half anequivalent amount, per equivalent of substituted sucoinic anhydride, ofan ethylene polyamine, and heating the resulting mixture 11 within thetemperature range of from about 80 C. to about 200 C. to effectacylation and to remove the waiter formed thereby.

3. The product prepared by the process which comprises mixing asubstituted anhtydride having the structural formula R-CH-CQ wherein Ris a large, substantially aliphatic hydrocarbon radical having at leastabout 50 carbon atoms, said substituted suceinic anthydride having beenprepared by the reaction of maleic anhydride with a chlorinated highmolecular weight olefin; with at least about onehalf an equivalentamount, per equivalent of substituted succinic anhydride, of an ethylenepolyamine, and heating the resulting mixture within the temperaturerange of from about 80 C. to about 200 C. to effect acylation and toremove the water formed thereby.

4. The product of the process of claim 1 wherein the large,substantially aliphatic hydrocarbon radical is de- 25 J. GREENWALD L MARCUS, WALTER rived from a polyisobutene.

12 5. The product prepared by the process which comprises mixing asubstituted succinic anhydride having the structural formula.

R-CH-CO References Cited by the Examiner UNITED STATES PATENTS 2,490,74412/49 Trigg et a1 252-34 2,604,451 7/52 Rocchini 252-5l.5 2,638,450 3/53White et a1. 252-5l.5

NICHOLAS S. RIZZO, Primary Examiner.

Examiners.

MODANCE,

ITED STATES PATENT OFFICE QEWECATE OF. CORRECTIN Patent No. 3,172,892March 9, 1965 William M. Le Suer et a1.

It is hereby certified that error appears in the above numbered patentrequiring correction and that the said Letters Patent should read ascorrected below.

Column 2, lines 60 to- 68, the equations should appear as shown belowinstead of as in the patent:

IIHCO 4 RCH=CHCHCO RCH=CH2 0 CHCO cn co CHCO\ R-CH=CHCHCO\ RCH CH Cl+ 0-0 cnco cn co Signed and sealed this 14th day of September 1965.

(SEAL) Attest:

ERNEST W. SWIDER EDWARD J. BRENNER Attesting Officer Commissioner ofPatents

1. THE PRODUCT PREPARED BY THE PROCESS WHICH COMPRISES MIXING ASUBSTITUTED SUCCINIC COMPOUND SELECTED FROM THE CLASS CONSISTING OFSUBSTITUTED SUCCINIC ACIDS HAVING THE STRUCTURAL FORMULA